1. Field of the Invention
The present invention relates to a limited-use digital versatile disc (DVD), such as a DVD-video disc that permits only a predetermined number of uses of a video movie. The preferred exemplary embodiment utilizes a dye disposed on the DVD that changes optical properties after being exposed to a DVD reader laser to insure that only a predetermined limited number (e.g., two) use(s) of the DVD are permitted.
2. Description of Related Art
Video rental stores have long rented video cassettes to customers. Video rental stores are now typically renting DVDs to customers in addition to video cassettes. Indeed, the number of DVD rentals is increasing with respect to the number of video cassette rentals and some movies are now even being released on DVDs before being released on video cassettes. The reasons for the increasing number of DVD rentals include, for example, the superior audio and visual quality provided by the DVDs, the faster ability to find a certain scene in the movie, the opportunity to exercise a menu option in some DVDs to view interviews with the actors and/or extra scenes that were cut from the movie, and the elimination of the need to rewind the movie after viewing it. The number of DVD rentals is expected to increase as the number of DVD players owned by customers grows.
Video stores typically rent a DVD for a fixed fee that enables the renter to view the video an unlimited number of times over a prescribed time period. This arrangement is similar to the typical transaction for video cassette rentals. Renters typically are required to pay additional daily rental fees if the video is kept beyond the prescribed initial time period. To accommodate this arrangement, video rental stores must keep detailed renter, accounting and inventory records—as well as check returned DVDs and return them to the rental inventory. The renter, on the other hand must view the rented video soon after acquiring it and then make a prompt return trip to the rental store (to minimize rental fees).
It would be desirable to simply sell non-returnable DVDs on a pay-per-view or limited-use basis. If this could be done, it would no longer be necessary for the video store to check and re-stock inventory returns or to administer complicated renter accounts and/or return/restocking costs. Renter refund costs would also be lowered since damaged DVDs would not be re-rented. In addition, the transaction can now be a sale rather than a rental thus facilitating its occurrence in any store, not just a specialty rental store. The ability to move the transaction from a specialty store to a store the potential customer already visits for other purchases is a significant benefit. Purchasers of limited-use DVDs would also benefit in that the hassles associated with substantially immediate viewing and/or returning of the rented DVDs could be eliminated. In addition, because of the economics of this limited use approach, the current difficulty of maintaining sufficient rental stock of hit movies to fully satisfy consumer demand is avoided.
There have been prior attempts to provide such pay-per-view or limited-use DVDs. For example, a Digital Video Express (DIVX) disc provided a pay-per-view version of a DVD (DIVX was commercially abandoned in 1999). The DIVX discs were purchased by customers at a price that was competitive with the price of a typical video rental and did not have to be returned to the store which sold the DIVX disc. The customers were able to view content of the DIVX disc an unlimited number of times for a prescribed period of time (e.g., 48 hours) after its initial use. The DIVX discs were encoded with computer software that would disable the discs from being played at the expiration of the prescribed period of time. After the initial period expired, customers could order additional viewing time through a connection between the DIVX reader and a telephone line.
Although the DIVX format demonstrates the long felt need of providing a limited-use DVD that does not have to be returned to the video store, the DIVX format had drawbacks that prevented its commercial success. For example, the DIVX system required a telephone line to be connected to the DIVX reader. The DIVX discs could not be viewed on computers having DVD-ROM disc drives. Additionally, DIVX discs could only be viewed by the DIVX reader that initially played the disc, and thus the content of the disc could not be viewed on another DIVX player.
An optical recording medium such as a DVD that prevents unauthorized copying of prerecorded data from the medium is known in the art. For example, U.S. Pat. No. 5,963,536—Vasic et al. (1999) discloses an optical recording medium comprising a prerecorded area for storing user data and a copy count area. The copy count area comprises a photosensitive layer that includes a material that permanently changes when exposed to a laser light from a conventional optical recording medium reader. The change in the optical properties of the photosensitive layer produces changes in the reflected laser light beam that are detectable during a subsequent reading by the reader.
Specifically, the photosensitive layer disclosed by Vasic et al. forms at least one ring in the copy count area, each ring corresponding to one authorized copy of the user data. After the rings have changed, a detectable change in the reflected light of the reader while reading the copy count information will result in a high user data bit error rate and a high tracking error rate. This high user data bit error rate and the high tracking error rate will inhibit the reader from reading the medium and copying the user data from the medium. The high user data bit error rate and the high tracking error rate resulting from the change in the optical properties of the photosensitive layer thus acts as an indicator to the reader that an authorized copy of the medium has already been made or that data from the medium has already been displayed.
Vasic et al. discloses another embodiment in which a photosensitive layer overlays a prerecorded area. The photosensitive layer is optically changed after one reading of the prerecorded area and renders the medium invalid for further reading or copying.
Other prior known attempts to provide an optical recordable device include the following:                U.S. Pat. No. 6,104,686-Whitcher et al. (2000)        
Published European Patent Application No. 09/32148-Pan et al. (1999).
Whitcher et al. discloses an optical recording disc that includes a layer of laser markable material such as a “write once” phase change material. The optical properties of the laser markable material are altered to cause the reflectivity of the material to be altered. It can thus be determined through the markable material whether the optical recording disc has been previously accessed.
Pan discloses an optical recordable device having a markable phase-change layer formed on a small portion of a transparent layer. The markable phase-change layer can change from an amorphous state to a crystalline state during heating by a laser read beam.
Various other types of optical storage mediums have been employed. For example, see:                U.S. Pat. No. 5,706,266-Brownstein et al. (1998)        U.S. Pat. No. 5,489,768-Brownstein et al. (1996)        U.S. Pat. No. 5,430,281-Lentz et al. (1995)        U.S. Pat. No. 4,961,077-Wilson et al. (1990)        U.S. Pat. No. 6,070,799-Ashe (2000)        U.S. Pat. No. 6,034,930-Kitahara (2000)        
Although these prior art examples demonstrate a long-felt need in the art for a limited-use DVD, at least some of them involve relatively complex structures which must be produced through complicated manufacturing processes or need special readers to operate the DVD properly.
Accordingly, there remains a need for an improved solution to this long-standing problem. The DVD of the present invention fills this need by employing a construction that permits only the limited use of a DVD and can be viewed using any standard DVD reader.
Even though a standard DVD reader has a relatively powerful microprocessor incorporated in it, there has conventionally not been any way for an entity other than the manufacturer of the DVD reader (during manufacture) to access its power and manipulate its capabilities. It has therefore been previously thought to be impossible, after a standard DVD reader was manufactured, to externally provide the DVD reader with a decision-making capability. Accordingly, their remains a need in the art to enable a standard DVD reader to have an externally-provided decision making capability. That is, there remains a need to create branching points for the operation of a DVD reader where one had not existed heretofore.